Culligan Proprietary Compatible TFC Membrane 35 GPD Yellow-Grey (pro)

Some Culligan filters have a double ''O'' ring at one end and some of their membranes have double ''O'' rings at both ends.Because of this, we call them ''proprietary,'' but we sell these filters and membranes which you can substitute in place of the original Culligan ones.Item# Culligan Proprietary TFC 35gpd Yellow/Grey